These studies are designed to evaluate the clinical benefits achieved by iron chelation in patients with chronic iron overload. Desferrioxamine is administered by subcutaneous infusion and iron removal is determined by quantitation of urinary iron excretion and careful recording of the total iron administration by transfusion. Over the past four years, 49 patients have participated in a randomized study to evaluate the safety of low dose ascorbic acid. Thirty patients took the desferal and ascorbic acid regularly for fours years and therefore were available for evaluation. Randomization was successful in that the two groups were equivalent. No evidence of ascorbic acid toxicity was noted and therefore we concluded that low doses of the vitamin may be safely given to enhance urinary iron excretion in young patients with thalassemia. During the past year we have initiated a collaboration with Dr. Gary Brittenham of the Cleveland Clinic. Using magnetic susceptability, Dr. Brittenham can estimate liver iron concentration accurately. This quantitative measurement will be obtained in our entire group of 65 patients and these data correlated with the amount of desferal administered and other clinical measurements of iron overload.